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This paper develops a conditional framework for understanding the emergence of measurable physical structure from a pre-metric domain. Contemporary physics provides powerful and precise descriptions of relations among already-defined…

History and Philosophy of Physics · Physics 2026-04-20 Jonathon Sendall

Starting from some results regarding the form of the Ricci scalar at a point $P$ in a spacetime endowed with a minimum distance, we investigate how they might be accommodated, specifically for the case of null separations, in a…

General Relativity and Quantum Cosmology · Physics 2022-10-12 Alessandro Pesci

The study of chaos in relativistic systems has been hampered by the observer dependence of Lyapunov exponents (LEs) and of conditions, such as orbit boundedness, invoked in the interpretation of LEs as indicators of chaos. Here we establish…

Chaotic Dynamics · Physics 2009-06-11 Adilson E. Motter , Alberto Saa

In [1], it is established that a convergent observer with an infinite gain margin can be designed for a given nonlinear system when a Riemannian metric showing that the system is differentially detectable (i.e., the Lie derivative of the…

Optimization and Control · Mathematics 2016-06-21 Ricardo G. Sanfelice , Laurent Praly

We explore the intimate connection between spacetime geometry and electrodynamics. This link is already implicit in the constitutive relations between the field strengths and excitations, which are an essential part of the axiomatic…

General Relativity and Quantum Cosmology · Physics 2017-02-14 Francisco Cabral , Francisco S. N. Lobo

I examine the debate between substantivalists and relationalists about the ontological character of spacetime and conclude it is not well posed. I argue that the so-called Hole Argument does not bear on the debate, because it provides no…

History and Philosophy of Physics · Physics 2021-03-04 E. Curiel

We propose a novel probabilistic dimensionality reduction framework that can naturally integrate the generative model and the locality information of data. Based on this framework, we present a new model, which is able to learn a smooth…

Machine Learning · Statistics 2016-10-18 Li Wang

We study state estimation for nonlinear differential-algebraic systems, where the nonlinearity satisfies a Lipschitz condition or a generalized monotonicity condition or a combination of these. The presented observer design unifies earlier…

Optimization and Control · Mathematics 2019-10-10 Thomas Berger , Lukas Lanza

Within a simple quantization scheme, observables for a large class of finite dimensional time reparametrization invariant systems may be constructed by integration over the manifold of time labels. This procedure is shown to produce a…

General Relativity and Quantum Cosmology · Physics 2010-04-06 Donald Marolf

In this paper, we study the mathematical structure and numerical approximation of elliptic problems posed in a (3D) domain $\Omega$ when the right-hand side is a (1D) line source $\Lambda$. The analysis and approximation of such problems is…

Numerical Analysis · Mathematics 2018-11-01 Ingeborg G. Gjerde , Kundan Kumar , Jan M. Nordbotten , Barbara Wohlmuth

In this paper we construct the Fermi coordinates along any arbitrary line in simple analytical way without use the orthogonal frames and their parallel transport. In this manner we extend the Eddington approach to the construction of the…

General Relativity and Quantum Cosmology · Physics 2020-09-17 V. A. Belinski

Recently, Bennett et al. [Eur. J. Phys. 37:014001, 2016] presented a physically-motivated and explicitly gauge-independent scheme for the quantisation of the electromagnetic field in flat Minkowski space. In this paper we generalise this…

Quantum Physics · Physics 2019-10-02 Ben Maybee , Daniel Hodgson , Almut Beige , Robert Purdy

We introduce an abstract framework for the study of clustering in metric graphs: after suitably metrising the space of graph partitions, we restrict Laplacians to the clusters thus arising and use their spectral gaps to define several…

Spectral Theory · Mathematics 2020-05-05 James B. Kennedy , Pavel Kurasov , Corentin Léna , Delio Mugnolo

Classical mechanics, relativity, electrodynamics and quantum mechanics are often depicted as separate realms of physics, each with its own formalism and notion. This remains unsatisfactory with respect to the unity of nature and to the…

History and Philosophy of Physics · Physics 2018-02-07 C. Baumgarten

We propose a novel family of entanglement measures for time-separated subsystems. Our definitions are applicable to any quantum system, continuous or discrete. To illustrate their utility, we derive upper and lower bounds on time-separated…

Quantum Physics · Physics 2025-12-16 Alexey Milekhin , Zofia Adamska , John Preskill

The principle of equivalence is used to examine covariant descriptions of quantum phenomena within the global exterior of geometries described using Painlev\'e- Gullstrand coordinates, which are everywhere non-singular away from their…

High Energy Physics - Theory · Physics 2019-06-05 Pradip Kattel , James Lindesay

While quantum field theory could more aptly be called the "quantum field framework" $-$ as it encompasses a vast variety of varying concepts and theories $-$ in comparison, relativity, both special and general, is more commonly portrayed as…

General Relativity and Quantum Cosmology · Physics 2019-06-27 Sebastian Schuster , Matt Visser

A formalism is derived to analyze the scattering of a conducting structure based on the characteristic modes of another structure whose surface is a superset of the first structure. This enables the analysis and comparison of different…

Signal Processing · Electrical Eng. & Systems 2025-12-10 Leonardo Mörlein , Dirk Manteuffel

We present a theoretical foundation for relativistic astronomical measurements in curved space-time. In particular, we discuss a new iterative approach for describing the dynamics of an astronomical N-body system. To do this, we generalize…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Slava G. Turyshev

The Separation of Variables theory for the Hamilton-Jacobi equation is 'by definition' related to the use of special kinds of coordinates, for example Jacobi coordinates on the ellipsoid or St\"ackel systems in the Euclidean space. However,…

Mathematical Physics · Physics 2009-07-20 Giovanni Rastelli